{"product_id":"carrier-ph3zna042000aa-transformer-h3025m","title":"OEM Carrier Transformer 75VA 208\/240\/480V–24V for PH3ZNA042000AA","description":"\u003ch1\u003eOEM Carrier 75VA Control Transformer (208\/240\/480V to 24VAC) for Model PH3ZNA042000AA\u003c\/h1\u003e\u003cp\u003eThis OEM Carrier control transformer (part #HT01BD242) is the factory-specified replacement for the \u003cstrong\u003eCarrier PH3ZNA042000AA\u003c\/strong\u003e fan coil unit. The transformer steps down high-voltage line power (208, 240, or 480V primary) to the 24VAC signal voltage that powers your thermostat, control board, and all low-voltage switching circuits. When this transformer fails, the entire control circuit goes dead — the thermostat becomes unresponsive, the system will not start, and you may find a blown 5-amp fuse or tripped breaker on the secondary side. It is one of the most commonly overlooked failure points in any HVAC system.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpecs:\u003c\/strong\u003e 75VA power rating | Primary input: 208V \/ 240V \/ 480V (multi-tap) | Secondary output: 24VAC | Frequency: 50\/60Hz | Foot-mount design | OEM Part #HT01BD242\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM vs Generic:\u003c\/strong\u003e OEM transformers are wound to exact factory VA tolerances, protecting downstream control boards from voltage sag under load. Generic units with loose VA ratings can cause erratic lockouts and premature board failures.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall difficulty: 2\/5\u003c\/strong\u003e — Shut off all power and verify zero voltage before touching any terminals. Tools needed: multimeter, screwdrivers (flat and Phillips), wire nuts or spade terminals. Always confirm primary tap wiring matches your supply voltage before energizing.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWarranty:\u003c\/strong\u003e 1-year OEM manufacturer warranty. In-stock units ship same business day from our warehouse.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eCompatibility:\u003c\/strong\u003e Factory-matched replacement for Carrier model \u003cstrong\u003ePH3ZNA042000AA\u003c\/strong\u003e fan coil units. This transformer is also cross-compatible with a wide range of Carrier, Bryant, Payne, Tempstar, Heil, and Comfortmaker equipment sharing the same 75VA multi-tap requirement — always verify primary voltage and VA rating on your unit's data plate before ordering. Have a fitment question? Our HVAC parts specialists verify compatibility before you buy — contact us today and get your system back online fast.\u003c\/p\u003e","brand":"Carrier","offers":[{"title":"OEM","offer_id":62641341956467,"sku":"CARRIE-PH3ZNA042000AA-TRANSFORMER-HT01BD242","price":70.2,"currency_code":"USD","in_stock":true},{"title":"Generic","offer_id":62641341989235,"sku":"CARRIE-PH3ZNA042000AA-TRANSFORMER-HT01BD242-GEN","price":23.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-transformer-control-HT01BD242_486c03cf-4677-4d52-b8d1-5d5e796ef608.jpg?v=1782943302","url":"https:\/\/nationalhvacparts.com\/products\/carrier-ph3zna042000aa-transformer-h3025m","provider":"National HVAC Parts","version":"1.0","type":"link"}